High frequency bus method

ABSTRACT

Certain exemplary embodiments can comprise a system comprising an electric drive system for a machine. The system can comprise a rectifier adapted to convert AC power from an alternator to DC power. The system can comprise an inverter adapted to receive DC power from the rectifier and provide power to a traction motor and/or auxiliary devices. Certain exemplary embodiments can comprise a system and method for dissipating excess energy from a machine.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims priority to, and incorporates by referenceherein in its entirety, pending U.S. Provisional Patent Application Ser.No. 60/574,958 (Attorney Docket No. 2004P08956US), filed 27 May 2004,pending U.S. Provisional Patent Application Ser. No. 60/574,959(Attorney Docket No. 2004P08957US), filed 27 May 2004, and pending U.S.Provisional Patent Application Ser. No. 60/592,547 (Attorney Docket No.2004P13018US), filed 30 Jul. 2004.

BACKGROUND

Mining equipment, such as large off-road mining trucks and excavators(e.g., shovels, draglines, etc.) can use relatively large AC and/or DCmotors to move the equipment and/or to move material. These motors caninclude propel motors, hoist motors, swing motors, and/or crowd motors.Such motors can be powered by conventional DC or AC electric-drivesystems. Such systems can include magnetic components, such astransformers, filters, reactors, etc., that can be of a significant sizeand/or weight.

Mining equipment can derive energy primarily from an internal combustionengine, which can be mechanically coupled to an alternator. Thealternator can provide an AC signal, for example, to auxiliary devices.The alternator can provide the AC signal to an electrical system thatcan have different configurations and concepts. The operating frequencyfor the auxiliary loads electrically coupled to the alternator can beapproximately 60 Hz.

Electrical systems can affect an idle speed of the internal combustionengine of the machine. Meeting auxiliary device power demand sometimescan involve maintaining a minimum engine speed above a level that mightotherwise be possible. For example, a conventional drive system canresult in an idle speed above approximately 1000 revolutions per minute(RPM) to adequately power the auxiliary devices in large mining trucks.The result of the elevated idle speed can be excessive use of fueland/or higher maintenance expense of the diesel engine, thereby causinghigher operational cost of the truck. Thus, there can be a need for asystem and/or method that can efficiently power auxiliary systems.

Machines can utilize high power traction drive systems that can generatesignificant amounts of heat. As a result, there can be a need foreffective cooling systems. Air-cooling can be used on machines wherelarge volumes of air are moved using blowers to cool components such asthe inverter power modules and traction motors. Limitations ofconventional air-cooling systems can include limited power densityand/or relatively large spatial footprints. Therefore, there can be aneed for a cooling system that can provide greater power density and/orhas a far smaller footprint than conventional air-cooled tractionsystems.

SUMMARY

Certain exemplary embodiments can comprise a system comprising aninternal combustion engine mechanically coupled to an alternator. Thealternator can be electrically coupled to a rectifier adapted to receivea first AC signal from the alternator. The rectifier can be electricallycoupled to a DC bus and can provide a DC signal to the DC bus. Thesystem can comprise an inverter electrically coupled to the DC bus. Theinverter can be adapted to provide a second AC signal to a tractionmotor and/or an auxiliary device.

BRIEF DESCRIPTION OF THE DRAWINGS

A wide variety of potential embodiments will be more readily understoodthrough the following detailed description, with reference to theaccompanying drawings in which:

FIG. 1 is a block diagram of an exemplary embodiment of an energymanagement system 1000;

FIG. 2 is a block diagram of an exemplary embodiment of an energymanagement system 2000;

FIG. 3 is a block diagram of an exemplary embodiment of an energymanagement system 3000;

FIG. 4 is a block diagram of an exemplary embodiment of an energymanagement system 4000;

FIG. 5 is a block diagram of an exemplary embodiment of a heatdissipation system 5000;

FIG. 6 is a block diagram of an exemplary embodiment of an invertercircuit 6000;

FIG. 7 is a diagram of an exemplary set of vectors 7000 associated withan inverter circuit;

FIG. 8 is an exemplary phase voltage waveform generated via Space VectorModulation;

FIG. 9 is a block diagram of an exemplary embodiment of a water cooledIGBT control box 9000;

FIG. 10 is a block diagram of an exemplary embodiment of a water cooledIGBT control box 10000;

FIG. 11 is a block diagram of an exemplary embodiment of a tractionmotor 11000;

FIG. 12 is a block diagram of an exemplary embodiment of an energymanagement method 12000; and

FIG. 13 is a block diagram of an exemplary embodiment of an informationdevice 13000.

DEFINITIONS

When the following terms are used herein, the accompanying definitionsapply:

-   -   a—at least one.    -   active—a circuit and/or device that uses transistors, integrated        circuits, and/or vacuum tubes to perform an action on an        electrical source.    -   active front end—a self-commutated, actively controlled line        converter; a self-commutated infeed/regenerative feedback unit.    -   activity—performance of a function.    -   adapted to—made suitable and/or fit for a specific use and/or        situation.    -   alternating current (AC)—an electric current that reverses        direction in a circuit at regular intervals.    -   alternator—a device adapted to convert mechanical energy to        electrical energy. For the purposes of this application, the        term “alternator” also includes generators.    -   apparatus—an appliance and/or device for a particular purpose.    -   approximately—nearly the same as.    -   automatic—performed via an information device in a manner        essentially independent of influence and/or control by a user.    -   auxiliary device—non-power train devices associated with a        vehicle, such as fans, blowers, windshield wipers, air        conditioning, heaters, and/or pumps, etc.    -   auxiliary power system—a plurality of electrically coupled        components adapted to deliver electrical power to auxiliary        devices.    -   bus—an electrical conductor that makes a common connection        between at least two circuits.    -   can—is capable of, in at least some embodiments.    -   comprising—including but not limited to.    -   constant—continually occurring; persistent; and/or unchanging.    -   continuously—uninterrupted in time, sequence, substance, and/or        extent.    -   control—to exercise authoritative and/or dominating influence        over; direct; adjust to a requirement; and/or regulate.    -   convert—to transform.    -   cool—to transfer thermal energy away.    -   cooling fluid—a fluid adapted to transfer heat energy.    -   correction—a change to a more desired value.    -   couple—to join, connect, and/or link two things together.    -   coupleable—adaptable to be connected.    -   crowd—to press, cram, and/or force together tightly.    -   DC chopper—a device adapted to modulate an unmodulated DC        voltage.    -   define—to establish the outline, form, and/or structure of.    -   de-rate—lower the rated electrical capability of an electrical        apparatus.    -   direct current (DC)—a non-alternating electric current.    -   double stator winding—a stationary part of a motor, dynamo,        turbine or other working electrical machine with two separate        windings on each pole. A rotor turns around the stator. Each of        the two windings is adapted to receive power from a separate        inverter.    -   drag—to cause to trail along a surface.    -   dragline—a large excavation machine used in surface mining to        remove overburden (layers of rock and soil). A typical dragline        casts a wire rope-hung bucket a considerable distance, collects        the dug material by pulling the bucket toward itself on the        ground with a second wire rope (or chain), elevates the bucket,        and dumps the material on a spoil bank, in a hopper, and/or on a        pile, etc.    -   drive—a means by which power is transmitted.    -   duty cycle—a fraction of time a system is actually employed in        performing its function; a percentage of time a DC voltage is        substantially non-zero.    -   electric—powered by electricity.    -   electrically coupled—objects connected or linked so as to allow        a flow of electrons there between.    -   excitation—a degree of intensity of an electromagnetic field in        an alternator caused by the application of a current to the        alternator stator.    -   filter-less—an electrical system lacking a device adapted to        reject signals of certain frequencies while allowing others to        pass.    -   fluid—a liquid, slurry, vapor, mist, cloud, plume, and/or foam,        etc.    -   fluid-to-air heat exchanger—a device adapted to transfer heat        from a fluid to air.    -   frequency—a number of electrical voltage and/or current        oscillations in a predetermined time period.    -   generating—producing electrical power.    -   harmonic current distortion—for an AC power signal, the ratio of        a sum of the powers of all harmonic frequencies above and/or        below a fundamental current frequency to the power of the        fundamental current frequency.    -   harmonic filter—a device comprising a capacitor bank and an        induction coil and that is designed and/or tuned to a        predetermined non-linear load to eliminate and/or substantially        attenuate a predetermined harmonic frequency range.    -   heat sink—a device adapted to transfer thermal energy away from        a connected object.    -   hoist—to lift and/or raise.    -   Hz—an abbreviation for Hertz, which is a unit of frequency equal        to one cycle per second.    -   input—related to electricity entering a device.    -   Insulated Gate Bipolar Transistor (IGBT)—a semiconductor device        that has identical operation to a bipolar transistor, but has a        field effect type gate, so that when a gate-emitter voltage is        applied to make it conductive, no current needs to be injected.        When gate-emitter voltage is very low the device switches off.    -   internal combustion engine—a device in which fuel is oxidized        such that energy within the fuel is converted to mechanical        energy, such as turning a shaft. The fuel can be gasoline,        diesel fuel, ethanol, methanol, and/or any other        hydrocarbon-based fluid, etc.    -   inverter—a device that converts DC power to AC power or AC power        to DC power.    -   limit—a point beyond which something cannot or may not proceed.    -   load—an amount of mined earthen material associated with a        bucket and/or truck, etc.    -   machine—a device and/or vehicle adapted to perform at least one        task.    -   material—any substance that can be excavated and/or scooped.    -   may—is allowed to, in at least some embodiments.    -   mechanically coupled—at least a first object and a second object        connected or linked so as to allow the first object to move        physically in concert with the second object.    -   method—a process, procedure, and/or collection of related        activities for accomplishing something.    -   mine—a site from which earthen materials can be extracted.    -   mining excavator—a machine for excavating material from the        earth.    -   mining haul truck—a motor vehicle adapted to haul an extracted        material.    -   modulated—varied with respect to frequency, amplitude, phase, or        other characteristic.    -   off-road traction vehicle—a vehicle adapted for operation on        earthen surfaces other than on paved surfaces. For example,        off-road traction vehicles can comprise mining trucks, electric        mining shovels, and/or electric mining excavators, etc.    -   operate—function.    -   output—something produced, and/or generated.    -   plurality—the state of being plural and/or more than one.    -   power—electrical energy usable to do work.    -   power factor—a ratio of true power to apparent power. A power        factor of 1.0 indicates that current and voltage are in phase.    -   power factor compensating equipment—equipment adapted to change        a phase relationship between an AC voltage and an AC current to        a more desired value.    -   power sink—a device adapted to dissipate electrical energy by        converting electrical energy usually to heat or mechanical        energy.    -   predetermined—established in advance.    -   propel—to cause to move forward and/or backward.    -   provide—supply.    -   Pulse Wave Modulated (PWM)—a method of regulating the output        voltage and frequency of a switching power supply by varying the        width, but not the height, of a train of pulses; and/or the        modulation of duty cycle of a signal and/or power source to        convey information over a communications channel and/or control        the amount of power sent to a load.    -   pump—a machine adapted to raise, compress, and/or transfer a        fluid.    -   receive—to take, get, acquire, and/or have bestowed upon.    -   rectifier—a device that converts AC power to DC power.    -   retard—to attempt to slow; to resist motion.    -   set—a related plurality.    -   shovel—an electrically powered device adapted to dig, hold,        and/or move ore.    -   signal—electrical power associated with, at any given time, a        particular current value and a particular voltage value, and,        across any particular range of time, the electrical power        characterized by at least one alternating current, direct        current, and/or voltage waves.    -   sin (sine)—the ordinate of the endpoint of an arc of a unit        circle centered at the origin of a Cartesian coordinate system,        the arc being of length x and measured counterclockwise from the        point (1, 0) if x is positive or clockwise if x is negative.    -   sine wave—a wave with deviation that can be graphically        expressed as the sine curve determinable by the equation        y=sin(x).    -   sine wave output current—an electrical current oscillating about        a central point wherein a graphical representation of the        oscillation resembles a sine wave.    -   sinusoidal filter—an electrically coupled reactor and capacitor        adapted to create sine waves of the output current of a        frequency drive.    -   space vector modulated (SVM)—a form of pulse width modulation        for regulating the output voltage and frequency of a signal        characterized by varying the width, but not the height, of a        train of pulses; and/or the time intervals between pulses. Space        vector modulated signals are distinguished from other forms of        pulse width modulated signals by the method of determining when        the pulses begin and end. Space vector modulated pulses are        timed via a calculated space vector.    -   speed—a velocity.    -   static—stationary and/or constant.    -   substantially—to a great extent and/or degree.    -   swing—to move laterally and/or in a curve.    -   switched capacitor bank—a plurality of capacitors adapted to be        automatically switched into an electrical power transmission        circuit, usually to correct a power factor.    -   system—a collection of mechanisms, devices, data, and/or        instructions, the collection designed to perform one or more        specific functions.    -   temperature—measure of the average kinetic energy of the        particles in a sample of matter, expressed in terms of units or        degrees designated on a standard scale.    -   temperature sensor—a device adapted to provide a signal        proportional to a temperature.    -   traction motor—an electric motor mechanically coupled to provide        motive force to move a machine.    -   unmodulated—substantially constant. For example, a relatively        constant DC voltage is unmodulated.    -   variable—likely to change and/or vary, subject to variation,        and/or changeable.    -   voltage—(a.k.a., “potential difference” and “electromotive        force” (EMF)) a quantity, expressed as a signed number of Volts        (V), and measured as a signed difference between two points in        an electrical circuit which, when divided by the resistance in        Ohms between those points, gives the current flowing between        those points in Amperes, according to Ohm's Law.    -   wave—a disturbance, variation, and/or incident that causes the        transfer electrical energy progressively from point to point in        a medium.    -   waveform—a profile, graph, and/or visual model of variations of        voltage and/or current over time.

DETAILED DESCRIPTION

FIG. 1 is a block diagram of an exemplary embodiment of an energymanagement system 1000. In certain exemplary embodiments, energymanagement system 1000 can be a part of a machine such as an off-roadtraction vehicle. The machine can be a vehicle, such as an automobile,pick-up truck, tandem wheel truck, bus, mining excavator, locomotive,and/or mine haul truck, etc. The machine can be a transport, anelevator, an industrial machine, etc. Energy management system 1000 cancomprise an alternator 1100. Alternator 1100 can be mechanically coupledto an internal combustion engine. Alternator 1100 can generate ACsignals thereby converting mechanical energy from the internalcombustion engine to electrical energy.

Energy management system 1000 can comprise a rectifier 1150. Rectifier1150 can comprise an active Insulated Gate Bipolar Transistor (IGBT).Rectifier 1150 can be adapted to convert AC signals to DC signals.Rectifier 1150 can provide DC signals to a DC bus 1175. The signalsprovided to the DC bus from the DC rectifier can have a voltage ofapproximately 120, 135.67, 159.1, 224.5, 455, 460.75, 885, 930.1, 1200,1455.45, 1687.1, 2000, 2200.32, 2300.12, 3000.6, 5500 Volts, and/or anyother value or range of voltages therebetween. The voltage on DC bus1175 can be varied by changing an internal combustion engine speed, theon and off duty cycle of rectifier 1150, and/or the excitation ofalternator 1100.

Energy management system 1000 can comprise a plurality of inverters1500, 1600, 1700, 1800, which can be adapted to drive a plurality oftraction motors 1900, 1950. Inverters 1500, 1600, 1700, 1800 can beactive IGBT inverters. Inverters 1500, 1600, 1700, 1800 can be adaptedto provide AC signals at a frequency of approximately 29.9, Hz, 40 Hz,48.75 Hz, 54.2 Hz, 60 Hz, 69.2 Hz, 77.32 Hz, 85.9 Hz, 99.65 Hz, 120 Hz,144.2 Hz, 165.54 Hz, 190.3, 240 Hz and/or any value or sub-range ofvalues therebetween.

Each of traction motors 1900, 1950 can comprise double stator windings.Motors comprising double stator windings can be adapted to operateand/or generate signals at a higher frequency. But even if frequency isnot increased, by utilizing AC motors having double stator windings, upto approximately double the torque can be achieved at the same motorline current value. Additional information on Double stator motortechnology can be found in U.S. Pat. No. 4,785,213 (Satake), which isincorporated by reference in its entirety.

Energy management system 1000 can comprise a circuit adapted todissipate energy generated via traction motors 1900, 1950 when themachine is operating under retard. The circuit can comprise a choppercircuit, which can be an active IGBT chopper circuit comprising one ormore active IGBT transistors 1300, 1350. Energy passing through an IGBT1300, 1350 can be dissipated via resistor 1400. Resistor 1400 can be aresistor, a grid resistor (or resistor array), or a plurality of gridresistors.

Each of inverters 1500, 1600, 1700, 1800 can be illustrated asindividual transistor devices for simplicity. Each of inverters 1500,1600, 1700, 1800 can comprise a plurality of transistors for each powerphase provided to traction motors 1900, 1950 such as illustrated in FIG.4. An inverter circuit supplying a phase for a stator winding cancomprise two switching devices for providing Pulse Width Modulated (PWM)or Space Vector Modulated (SVM) signals to traction motors 1900, 1950.

Various algorithms can be used by information device 1200 to controlswitching in energy management system 1000. In order to understand theoperation of the circuitry in energy management system 1000, a simplercircuit can be analyzed. For example, each set of three phases ofsignals supplied to traction motors 1900, 1950 can comprise sixswitching devices (as illustrated for a single three phase power supplyin FIG. 6). Each of inverters 1500, 1600, 1700, 1800 can be controlledvia an information device 1200.

FIG. 6 is a block diagram of an exemplary embodiment of an invertercircuit 6000. For a three phase system, a first phase can be denotedphase “A,” a second phase can be denoted phase “B,” and a third phasecan be denoted phase “C.” Using similar nomenclature, the associatedswitching devices can be denoted as SA+, SA−, SB+, SB−, SC+ and SC−.Each set of six switching devices can be connected into a bridge circuitbetween connection points to DC bus 6100. The switching devices can beoperated by PWM switching or SVM switching controlled by informationdevice 6300. Information device 6300 can be adapted to provide switchingsignals responsive to a calculated command vector.

Since one of the two switches for each phase of power can be turned on,the switching states of each phase provided to traction motor 6200 canbe represented by three binary numbers (SA, SB, SC). For thisrepresentation, a “1” can indicate that the upper or + switching deviceis on and a “0” can indicate that the lower or − switching device can beon. Thus, (0, 0, 0) indicates that SA−, SB− and SC− are on and SA+, SB+and SC+are off; (1, 0, 0) indicates that SA+, SB− and SC− are on andSA−, SB+ and SC+are off; etc.

Each of the eight resulting coordinate sets can be modeled as switchingor voltage vectors V0 through V7 as shown in FIG. 7 with (0, 0, 0) or V0and (1, 1, 1) or V7 being zero vectors. The hexagon spanned by the sixnon-zero voltage vectors V1 through V6 can be divided into six 60°regions, 1 through 6, and each region can be spanned by two non-zerovoltage vectors. The magnitude or length of each non-zero voltage vectorcan be equal to 2V/3 where V can be the magnitude of the voltage on theDC bus.

Vectors can be represented by their projections onto X and Y axessuperimposed onto the hexagon spanned by the vectors V1 through V6. Forexample, the voltage command vector V_(s)* can be projected to defineV_(x)* and V_(y)* as shown in FIG. 7. The projections of each non-zerovector onto the X and Y axes can be determined from the equations:V _(i,x)=2·V/3·[cos((^(i−)1)60°)]  (1)V _(i,y)=2·V/3·[sin((i−1)60°)]  (2)where i can be the index of the vectors (i.e., i=1 represents voltagevector V1, i=2 represents voltage vector V2, and so forth); i can alsobe interpreted as the index for the regions 1 through 6.

A number of known PWM or SVM control arrangements can be used to controlthe switching devices SA+, SA−, SB+, SB−, SC+ and SC− to generate athree phase balanced set of AC voltages from the fixed DC voltage V. ForSVM, a voltage command vector rotating in the X-Y plane can represent abalanced three phase voltage command. For each pulse width modulationcontrol period, a three phase voltage command can be represented by avoltage command vector in the X-Y plane spanned by the six non-zerovoltage vectors V1 through V6 available, for example, from the invertercircuit 6000 of FIG. 6. Each voltage command vector can be approximatedor constructed by combining properly proportioned vectors which can bealigned with the two adjacent non-zero vectors and an appropriate one ofthe zero vectors, V0 or V7.

For example, as shown in FIG. 7 for the first sector, the voltagecommand vector V*_(s) can be approximated by V*₁, V*₂ and one of thezero vectors, V0 or V7. Zero vectors can be chosen so that only one ofthe switching devices SA+, SA−, SB+, SB−, SC+ and SC− needs to changeits on/off state for each transition from one non-zero vector to thezero vector to the next non-zero vector. The size or time span for eachof the voltage vectors can be selected to balance the volt-secondscommanded by the command vector and the actual volt-seconds applied, forexample, by the inverter circuit 6000 of FIG. 6.

In certain exemplary embodiments of SVM a sampling interval, T_(S), muchsmaller than ⅙ cycle of the intended output fundamental, can beassigned. Once the vector components are determined, within eachsampling interval the vector components can be considered as a timeweight ratio. The switches can operate to apply each of two activevectors for a specific fraction of T_(S). Then zero state intervals canbe added to make the total time come out to T_(S). This can beconsidered a PWM process, in the senses that the average behavior overmany T_(S) intervals tracks the desired output vector, and that the timeweights can be interpreted as duty ratios. In practice, the vectorcomponents can be re-computed at each time kT_(S), where k can be aninteger. Thus these times can serve as uniform sampling intervals, andthe average behavior over each interval can be determined by the voltagevector at time kT_(S).

FIG. 8 illustrates an example of an SVM process in time domain, given aswitching frequency that can be 15 times the intended fundamental outputfrequency (the modulation frequency) and 95% modulation relative to asine. The switching sequence can be as shown at the bottom of FIG. 8.The equivalent distorted modulation, with the reference sinusoid forphase a, can be as shown at the top of FIG. 8. In Sector I, the switchsequence can be 0-4-6-7-64-0 such that only one switch changes state ata time. The sequences for the other sectors can be obtained from FIG. 3.In a given sector, the vector-domain form of the desired output voltagecan be expressed as: $\begin{matrix}{{\overset{\rightarrow}{v}}_{out} = {{\frac{T_{i}}{T_{s}}{\hat{v}}_{i}} + {\frac{T_{j}}{T_{s}}{\hat{v}}_{j}}}} & (3)\end{matrix}$in which vector components T_(i)/T_(s) and T_(j)/T_(s) can become timeweights associated with switch states associated with each respectiveregion. The total time T_(s)=T_(i)+T_(j)+T₀+T₇ can be the samplinginterval. Zero state durations T₀ and T₇ can be arbitrary, providedtheir sum gives the correct T_(S), which shows that there can be adegree of freedom. In SVM, each zero state can be applied for anidentical interval, to give T₀=T₇.

A scaling factor can be introduced in the space-vector definitions. Thevector scale in space-vector domain can be 3 m/4, where m can be themodulating depth for each phase voltage (with associated with fullsinusoidal modulation). The factor of ¾ can be derived first by notingthat m is determined by $\begin{matrix}{m = \frac{V_{p\quad h}}{\frac{V}{2}}} & (4)\end{matrix}$where V_(ph) is the peak output phase voltage. The (balanced)time-domain phase voltages can be transformed to coordinates using anun-normalized Park transformation, via a factor of 3/2. As a result, thescaling from phase voltages to the desired output vector can become:$\begin{matrix}{{\overset{\rightarrow}{V}}_{out} = {{\begin{pmatrix}1 & {- \frac{1}{2}} & {- \frac{1}{2}} \\0 & {- \frac{\sqrt{3}}{2}} & \frac{\sqrt{3}}{2} \\\frac{1}{2} & \frac{1}{2} & \frac{1}{2}\end{pmatrix}\begin{pmatrix}{V_{p\quad h}{\cos\left( {\omega\quad t} \right)}} \\{V_{p\quad h}{\cos\left( {{\omega\quad t} - \frac{2\quad\pi}{3}} \right)}} \\{V_{p\quad h}{\cos\left( {{\omega\quad t} + \frac{2\quad\pi}{3}} \right)}}\end{pmatrix}} = {\frac{3}{4}{{mV}\begin{pmatrix}{\cos\left( {\omega\quad t} \right)} \\{\sin\left( {\omega\quad t} \right)}\end{pmatrix}}}}} & (5)\end{matrix}$

To relate this to a time domain, the normalized voltage components canbe associated with time functions M_(d)(t)=m cos(ωt) and M_(q)(t)=mcos(ωt), respectively.

Thus, the normalized output voltage vector can be written as {rightarrow over (v)}_(out)=(¾)M_(d)(t){circumflex over (v)}_(q). In SVM abasis with the axes in FIG. 7 can be transformed into a basis in an i-jcoordinate system with (with basis vectors B_(ij)) to find T_(i) andT_(j) and in (3). In Sector I, the basis vectors are {circumflex over(v)}₄ and {circumflex over (v)}₆, related to the x-y coordinate systemby $\begin{matrix}{\begin{pmatrix}{\hat{v}}_{4} \\{\hat{v}}_{6}\end{pmatrix} = {P\begin{pmatrix}{\hat{v}}_{x} \\{\hat{v}}_{y}\end{pmatrix}}} & (6)\end{matrix}$where is P can be a 2×2 transformation matrix that can be sectordependent.

The transformation matrices can be as shown in Table I for all sectors.TABLE I Sector I Sector II Sector III $\begin{matrix}{B_{ij} = \left\{ {{\hat{v}}_{4}\quad{\hat{v}}_{6}} \right\}} \\{P = \begin{pmatrix}1 & 0 \\\frac{1}{2} & \frac{\sqrt{3}}{2}\end{pmatrix}}\end{matrix}\quad$ $\begin{matrix}{B_{ij} = \left\{ {{\hat{v}}_{6}\quad{\hat{v}}_{2}} \right\}} \\{P = \begin{pmatrix}\frac{1}{2} & \frac{\sqrt{3}}{2} \\\frac{- 1}{2} & \frac{\sqrt{3}}{2}\end{pmatrix}}\end{matrix}\quad$ $\begin{matrix}{B_{ij} = \left\{ {{\hat{v}}_{2}\quad{\hat{v}}_{3}} \right\}} \\{P = \begin{pmatrix}\frac{- 1}{2} & \frac{\sqrt{3}}{2} \\{- 1} & 0\end{pmatrix}}\end{matrix}\quad$ Sector IV Sector V Sector VI $\begin{matrix}{B_{ij} = \left\{ {{\hat{v}}_{3}\quad{\hat{v}}_{1}} \right\}} \\{P = \begin{pmatrix}{- 1} & 0 \\\frac{- 1}{2} & \frac{- \sqrt{3}}{2}\end{pmatrix}}\end{matrix}\quad$ $\begin{matrix}{B_{ij} = \left\{ {{\hat{v}}_{1}\quad{\hat{v}}_{5}} \right\}} \\{P = \begin{pmatrix}\frac{- 1}{2} & \frac{- \sqrt{3}}{2} \\\frac{1}{2} & \frac{- \sqrt{3}}{2}\end{pmatrix}}\end{matrix}\quad$ $\begin{matrix}{B_{ij} = \left\{ {{\hat{v}}_{5}\quad{\hat{v}}_{4}} \right\}} \\{P = \begin{pmatrix}\frac{1}{2} & \frac{- \sqrt{3}}{2} \\1 & 0\end{pmatrix}}\end{matrix}\quad$

Sector I can be used as the basis for a discussion applying to eachrespective sector. The matrix P can relate to basis vectors. For thislinear transformation, the components can be related such that the i-jvector components in column form are (P⁻¹)^(T) times the x-y components.Thus components T₄/T_(s) and T₆/T_(s) can be computed as:$\begin{matrix}{\begin{pmatrix}\frac{T_{4}}{T_{s}} \\\frac{T_{6}}{T_{s}}\end{pmatrix} = {{\left( P^{- 1} \right)^{T}\begin{pmatrix}{\frac{3}{4}{M_{d}(t)}} \\{\frac{3}{4}{M_{q}(t)}}\end{pmatrix}} = {\begin{pmatrix}1 & {- \frac{1}{\sqrt{3}}} \\0 & \frac{2}{\sqrt{3}}\end{pmatrix}\begin{pmatrix}{\frac{3}{4}{M_{d}(t)}} \\{\frac{3}{4}{M_{q}(t)}}\end{pmatrix}}}} & (7)\end{matrix}$

The time argument in (7) can utilize sampling to support durationcomputations. At the sampling times, (7) can be expressed as:$\begin{matrix}{{\frac{T_{4}}{T_{s}} = {{\frac{3}{4}{M_{d}\left( {kT}_{s} \right)}} - {\frac{\sqrt{3}}{4}{M_{q}\left( {kT}_{s} \right)}}}}{\frac{T_{6}}{T_{s}} = {\frac{\sqrt{3}}{2}{{M_{q}\left( {kT}_{s} \right)}.}}}} & (8)\end{matrix}$

Typically, a separate information device tracks the switch sequence thatcan minimize a number of transitions.

Additional information on Space Vector Modulation can be found in U.S.Pat. No. 5,552,977, U.S. Pat. No. 6,023,417, U.S. Pat. No. 6,316,895,U.S. Pat. No. 6,819,078, and U.S. Pat. No. 6,839,249 which areincorporated by reference in their entirety, and from Alexis Kwasinski,Philip T. Krein, and Patrick L. Chapman, Time Domain Comparison ofPulse-Width Modulation Schemes, IEEE Power Electronics Letters, Vol. 1,No. 3 (September 2003).

Certain exemplary embodiments use a direct-reverse SVM technique tocontrol IGBTs in inverters 1500, 1600, 1700, 1800, which can reduceswitching losses in the IGBTs and/or provide extended utilization of thevoltage of DC bus 1175 when compared to other PWM methods.

FIG. 2 is a block diagram of an exemplary embodiment of an energymanagement system 2000. In certain exemplary embodiments, energymanagement system 2000 can comprise an internal combustion engine 2100.Internal combustion engine 2100 can be mechanically coupled to a firstalternator 2200 and a second alternator 2300. First alternator 2200 andsecond alternator 2300 can be controlled by a regulating circuit. Theregulating circuit can comprise a field regulator 2600, a thirdalternator 2400 and a rectifier and coil set 2500. The regulatingcircuit can be adapted to change an excitation current to firstalternator 2200 and second alternator 2300 thereby changing a voltageproduced by first alternator 2200 and second alternator 2300.

First alternator 2200 can be adapted to provide signals to a rectifier2700. Rectifier 2700 can be an active IGBT rectifier, which can receiveAC signals from the first alternator 2200 and provide DC signals to a DCbus. The DC bus can be adapted to provide signals to a first inverter2900 and a second inverter 2925. First inverter 2900 and second inverter2925 can be active IGBT inverters, which can operate under normalconditions receiving DC signals from the DC bus and provide AC signalsto first traction motor 2950 and second traction motor 2975. When themachine associated with energy management system 2000 is under retard,traction motor 2950 and traction motor 2975 can generate electricalsignals. When traction motor 2950 and traction motor 2975 act aselectric generators, such as when the machine is under retard, firstinverter 2900 and second inverter 2925 can be adapted to receive ACsignals from traction motor 2950 and traction motor 2975 and provide DCsignals to the DC bus.

Second alternator 2300 can be adapted to provide signals to an auxiliarysystem 2875. Second alternator 2300 can be electrically coupled to aswitch set 2800. Switch set 2800 can be adapted transfer the powersupply to auxiliary system 2875 from second alternator 2300 and acircuit adapted to provide power to auxiliary system 2875 while themachine is under retard.

Switch set 2800 can be electrically coupled to an auxiliary transformer2850. Auxiliary system 2850 can be adapted to change a voltage ofsignals supplied to auxiliary system 2875. For example, auxiliarytransformer 2850 can reduce a voltage output by second alternator 2300to a lower voltage for auxiliary system 2875.

FIG. 3 is a block diagram of an exemplary embodiment of an energymanagement system 3000. Energy management system 3000 can comprise aninternal combustion engine 3100. Energy management system 3000 cancomprise a first alternator 3300 and a second alternator 3400. Energymanagement system 3000 can comprise a field regulating circuit adaptedto change an output voltage of first alternator 3300. The fieldregulating circuit can comprise second alternator 3400 magneticallycoupled to a field regulator 3500. Second alternator 3400 can beelectrically coupled to a rectifier and coil set 3200. Field regulator3500 can be adapted to change a voltage and/or current output fromsecond alternator 3400. Rectifier and coil set 3200 can be adapted totransfer electrical current from second alternator 3400 to provide atime-variable excitation to first alternator 3300. First alternator 3300can be adapted to produce 3-phase AC signals.

First alternator 3300 can be electrically coupled to a rectifier 3600,which can be electrically coupled to a DC bus 3700. Rectifier 3600 canbe an active IGBT rectifier, which can comprise an input reactor, aplurality of IGBT transistors and anti parallel diodes in a 6-pulsebridge configuration, low inductance bus connections, a firing circuitto turn on/off the IGBTs, current and voltage transducers, and/or adigital control circuit, etc.

Rectifier 3600 can be adapted to provide DC signals to DC bus 3700.Rectifier 3600 can draw sinusoidal current irrespective of load and/orsupply conditions. In certain machines, rectifier 3600 can be a threephase full wave uncontrolled unit (i.e. diodes). In certain exemplaryembodiments, rectifier 3600 can be filter-less. Rectifier 3600 can beadapted to limit harmonic current distortion to a value of approximately5 percent, 4.02 percent, 2.998 percent, 2 percent, 1.1 percent, and/or0.5 percent, etc. or any value or subrange therebetween. Rectifier 3600can be adapted to provide an active input power factor correction toapproximately 0.95, 0.96, 0.97, 0.98, 0.99, and/or 1.00, etc. or anyvalue or subrange therebetween. In certain exemplary embodimentsrectifier 3600 can be adapted for use on mining shovels and/ordraglines.

DC bus 3700 can be electrically coupled to inverters 3725, 3750.Inverters 3725, 3750 can be active IGBT inverters. Inverters 3725, 3750can generate a space vector modulated (SVM) AC signal. Inverters 3725,3750 can be adapted to provide a sinusoidal output current irrespectiveof load and/or supply conditions, with less than approximately 7percent, 6.01 percent, 5 percent, 3.997 percent, 3 percent, 2.1 percent,and/or 1 percent total harmonic distortion or any value or subrangetherebetween.

Inverters 3725, 3750 can be adapted to generate a Space Vector Modulatedsinusoidal AC voltage having a duty cycle that can be continuouslyvaried to affect the time-averaged voltage output to, for example,traction motors 3925 and 3950. The output voltage of inverters 3725 and3750 can be varied in frequency, phase shift, and/or magnitude or a rootmean square value thereof, etc. Inverters 3725, 3750 can be adapted toreceive DC signals from DC bus 3700 and to deliver AC signals, such as3-phase AC signals, to traction motors 3925, 3950 when the machineassociated with energy management system 3000 is under propulsion.Traction motors 3925, 3950 can be mechanically coupled to axles andwheels adapted to propel the machine. When the machine is under retard,traction motors 3925, 3950 can be adapted to generate AC signals. Whentraction motors 3925, 3950 generate AC signals, inverters 3725, 3750 canbe adapted to provide DC signals to DC bus 3700.

Energy management system 3000 can comprise an auxiliary system inverter3775. Auxiliary system inverter 3775 can be adapted to output variable3-phase AC signals. Inverter 3775 can generate an AC waveform having afrequency of approximately 60, 90, 120, and/or greater cycles/second(hertz) and a magnitude of from approximately 100 to approximately 1800volts, including all values and subranges therebetween, such asapproximately 460, 600, and 720 volts, etc. Auxiliary system inverter3775 can be an active IGBT inverter. Auxiliary system inverter 3775 canbe adapted to generate a sine wave Pulse Wave Modulated DC voltage.

Inverter 3775 can be controlled utilizing an AC voltage sensor that canbe connected at the filtered output of three-phase transformer 3790 forthe regulation of the output AC voltage by controlling a modulationindex of inverter 3775. The set modulation index can be calculated orlooked up from a table based upon the main DC link voltage value. Incertain exemplary embodiments, after a modulation index is ramped up,the three-phase bus voltage can be tuned using the AC voltage sensor toa desired root mean squared value. The AC voltage sensor can becontinuously used to regulate the voltage value within +/−5% toleranceas a load is changing on the AC side. A load on a filtered section sideof inverter 3775 can be constant and 100% duty, which can reduce achance of having over voltage at light loads due to a sinusoidal filter.The sinusoidal filter can be electrically coupled to auxiliary systeminverter 3775.

Auxiliary system inverter 3775 can be adapted to provide power to anauxiliary system 3900 comprising auxiliary devices associated with themachine. Auxiliary system inverter 3775 can be adapted to receive DCsignals from DC bus 3700 and provide AC signals to auxiliary system3900. Auxiliary inverter 3775 can be electrically coupled to atransformer 3790 and/or sinusoidal filters. Transformer 3790 can beadapted to receive AC signals from auxiliary system inverter 3775 at afirst voltage and provide AC signals of a second voltage to auxiliarysystem 3900. Auxiliary system inverter 3775 can generate a SinewavePulse Wave Modulated (SPWM) DC voltage having a duty cycle (“on time”)that can be continuously varied to affect the time-averaged voltageoutput to, for example, the motors. Auxiliary system inverter 3775and/or inverters 3725 and 3750 can use a Space Vector Pulse WaveModulation (SVPWM) technique instead of SPWM. Auxiliary inverter 3775can utilize SPWM or SVM methods based on the load requirements and/ordetails of the implementation.

Auxiliary system inverter 3775 can comprise a medium power rating suchas 400 KVA, which can be used as an auxiliary power supply for auxiliarysystem 3900. For example, auxiliary system inverter 3775 can be aSiemens ST 1500 WL module or a Siemens ST1500 FL module (wherein the1500 WL module is water cooled and the ST1500 FL module is forced aircooled). Auxiliary system inverter 3775 can run as a PWM voltage sourceinverter fed from DC bus 3700. Transformer 3790 can be a three-phasetransformer and/or can provide isolation and/or can step down thevoltage supplied to auxiliary system 3900. Transformer 3790 can lack ahigher leakage impedance for filtering purposes. The unfiltered outputof the transformer can feed AC motors running a main blower and/or abraking resistor blower. A blower motor can be started using contactorsand/or a 50% tap winding starter on the secondary of the transformer.Three phase series filters, air core reactors, and/or a three-phasedelta connected capacitor bank can feed a water pump and/or a blower foran inside room cooler.

Auxiliary system 3900 can comprise an unfiltered three-phase AC bus thatcan feed, for example, a blower adapted to cool a traction motor,alternator, heat exchanger, and/or a braking unit, etc. The AC motorrunning this blower can be connected via a secondary winding tapstarter. A filtered three phase bus in auxiliary system 3900 can feed awater pump driven by an AC motor and/or a blower for an inside roomcooler driven by an AC motor. To minimize the size and/or weight of themagnetic components in auxiliary system 3900, the base frequency can beselected as approximately 120 Hz. AC motors in auxiliary system 3900 canrun off of a 440V/120 Hz supply. As a general approximation; for mineelevations under 10,000 feet, motors can be run at 367V/100 Hz, and forhigher elevations, motors can run at full 440V/120 Hz

In embodiments operating at 120 Hertz (compared to 60 Hz) for a ratedoutput voltage and maintaining an approximately constantvoltage/frequency (V/f) slope for other operating points, the size oftransformer 3790 can be decreased approximately in half, therebyreducing the size, footprint, and/or weight of the transformer with asimilar ratio. Based on the rated vehicle pay load, this weight savingscan translate to higher truck utilization through added pay loadcapability and/or higher volume per truck per day which can varydepending on a haul cycle.

In certain exemplary embodiments, the speed of internal combustionengine 3100 can be lowered as compared to conventional machines that canbe required at idle at a higher speed to appropriately power the truck'sauxiliary system. Auxiliary system 3900 can receive an AC signal from athree-phase auxiliary supply that can be fed from DC bus 3700. Incertain exemplary embodiments, DC bus 3700 can be charged by a DC signalgenerated via traction motors 3925, 3950, which act as generators duringelectrical braking and hence provide electrical energy. The energyprovided thereby to auxiliary system inverter 3775 can enable auxiliarysystem to be independent from internal combustion engine 3100, therebyallowing internal combustion engine 3100 to go into true idle (which canbe based on the specification of the diesel engine manufacturer, and canbe below approximately 1000, 900.05, 799.9, and/or 750.3 rpm, etc.).Using energy generated via traction motors 3925, 3950 can reduce machinefuel consumption and/or increase equipment life. In normal drivingconditions (e.g., propel mode), power for auxiliary system 3900 can comefrom internal combustion engine 3100.

Certain exemplary embodiments can act as a “true brake,” that is, theycan allow internal combustion engine 3100 to shut down while the machineis braking. A true brake can safely stop a moving machine even in thecase of a loss of power from internal combustion engine 3100. In thiscase, since power can be generated by traction motors 3925, 3950, theelectric brake (comprised in DC choppers and/or braking resistor unit)can operate independently of internal combustion engine 3100, i.e., noenergy need be fed through alternator 3400 from internal combustionengine 3300 since energy can come from traction motors 3925, 3950.

Auxiliary system 3900 can be designed for a higher frequency than thestandard 50 or 60 Hz. In certain exemplary embodiments, the auxiliarysystem can be designed to operate at frequencies from approximately 100to approximately 120 Hz, rated voltages up to approximately 460V, thus,still allowing use of standard NEMA motors that can be rated atapproximately 60 Hz and/or 460V as long as sufficient torque isavailable for the loads. Also, higher frequencies can allow the size oftransformer 3790 to be reduced significantly along with its weight,cost, and/or foot print. This can save weight on the machine and/orallow for better utilization and/or more efficient haul cycles.

In certain exemplary embodiments, motor loads in auxiliary system 3900can be continuous duty with the exception of an AC motor running thebraking resistor blower, which can be connected on-line through an ACmotor starter and ramped up to full speed. The power rating of thisblower can be approximately 50% of the overall power loading ofauxiliary system 3900.

The main DC link voltage feeding the auxiliary system inverter 3775 canbe variable between approximately 1200V and 2000V. The chassis of themachine can be grounded through a floating ground with a resistor ratioof approximately 1:3 (e.g., the frame can be approximately 667 voltsbelow main DC link positive and approximately 1334V above main DC linknegative). The AC motors used on the secondary side can be conventionalNEMA B AC motors adapted to operate at approximately 440V/60 Hz.

When a machine is started up, the output of auxiliary system inverter3775 can be ramped up to a voltage value that corresponds to anoperating frequency based on the V/f curve. The operating frequency canbased on a terrain profile and/or elevation (e.g., approximately 90Hz<f<approximately 120 Hz). The voltage ramp from zero need not causeany inrush currents while starting connected AC motors in auxiliarysystem 3900 (e.g., pump, traction motor cooler blower, and/or alternatorcooler blower). In addition, the start up can be within reasonable time(e.g., approximately 15 to approximately 20 seconds).

An AC voltage sensor can be connected at a filtered output oftransformer 3790 for the regulation of an output AC voltage bycontrolling a modulation index of auxiliary system inverter 3775. Themodulation index can be calculated (or looked up in a table) from thevoltage value of DC bus 3700. After the modulation index is ramped up,the three phase bus voltage can be tuned using the AC voltage sensor toa required root mean square value. The AC voltage sensor can becontinuously used to regulate the voltage value within +/−approximately5% tolerance as the load is changing on the AC side. The load on thefiltered section side can be constant and approximately 100% duty, whichcan reduce the chance of having over-voltage at light loads due to asinusoidal filter.

Certain exemplary embodiments can, as a result of using a base frequencyof approximately 120 Hz in auxiliary system 3900, reduce the footprintof auxiliary system 3900; reduce the weight of magnetic componentsemployed in auxiliary system 3900; improve a machine (since “dead” loadshauled by the machine can be reduced); improve utilization of brakingenergy of traction motors 3925, 3950; reduce the energy that can bewasted as heat in resistive elements dissipating braking energy fromtraction motors 3925, 3950; reduce maintenance; reduce running costs;increase life for internal combustion engine 3100; and/or reduce a costof an AC motor starter that can utilize a 50% tap on a secondary windingof transformer 3790 for starting motors that can operate with a partialduty cycle in auxiliary system 3900, etc.

Certain exemplary embodiments of auxiliary system 3900 can have thecharacteristics listed in Table II. TABLE II Max altitude High MediumLow Hp Kw Hp Kw hp Kw hp Kw Pump 5 3.7 5 3.7 5 3.7 5 3.7 Alternator 5541.0 48 35.8 40 29.8 32 23.9 Traction 90 67.1 80 59.7 75 56 70 52.0 Gridbox 90 67.1 85 63.4 85 63.4 52 38.8 Peak cont. Power 240 179 218 163 205152 159 118 Load after filter 253 188 229 171 213 159 173 129 Load afterST mod 263 196 239 178 221 165 180 134 Load on DC link 271 202 246 184228 170 185 138 Output trafo current 263 239 221 180 Altitude [ft] [m]16,000 4877 12,000 3658 8,000 2438 1 0 Estimated frequency [Hz] 120 110100 90 Total KVA, cont Peak 200 182 169 137 Continuous Power 150 112 13399 117 87 112 84 Load after filter 158 118 140 104 123 92 118 88 Loadafter ST mod 164 123 146 109 128 96 123 92 Load on DC link 170 126 150112 132 99 127 94 Output trafo current 164 146 128 123 Altitude [ft] [m]16,000 4877 12,000 3658 8,000 2438 — 0 Estimated frequency [Hz] 120 110100 90 Total KVA, cont Peak 125 111 98 94

Using auxiliary system inverter 3775 can allow the internal combustionengine to idle at a speed such as below approximately 1001, 900.3,799.75, and/or 750 rpm, etc. or any value or subrange therebetween.

Energy management system 3000 can comprise an information device 3950,which can be communicatively coupled to devices such as field regulator3500, rectifier and coil set 3200, rectifier 3600, inverter 3725,inverter 3750, and/or inverter 3775. Information device 3950 can, forexample, provide information adapted to generate SVM signals frominverter 3725, inverter 3750, and/or inverter 3775.

In certain exemplary embodiments, energy management system 3000 can lacka switched capacitor bank, power factor compensating equipment, and/orharmonic filter, etc.

FIG. 4 is a block diagram of an exemplary embodiment of an energymanagement system 4000. Energy management system 4000 can comprise aninternal combustion engine 4100 associated with a machine and/orvehicle. Energy management system 4000 can comprise an alternator 4200,which can be mechanically coupled to internal combustion engine 4100.Energy management system 4000 can comprise an excitation circuit 4150.Excitation circuit 4150 can be adapted to change excitation ofalternator 4200 thereby changing a voltage generated by alternator 4200.Alternator 4200 can comprise instrumentation adapted to monitor aplurality of conditions. For example, sensors can monitor a bearingvibration, bearing temperature, stator temperature, excitation current,current produced, and/or voltage produced, etc. Instrumentation canprovide information useful in operating and/or maintaining the machineand/or vehicle.

Alternator 4200 can be electrically coupled to a rectifier 4300.Rectifier 4300 can comprise active IGBT components. Rectifier 4300 canbe adapted to receive AC signals from alternator 4200 and convert the ACsignals to DC signals. Rectifier 4300 can be adapted to provide DCsignals to a first section of a DC bus 4400 and a second section of theDC bus 4450.

The first section of the DC bus 4400 and the second section of the DCbus 4450 can receive signals from rectifier 4300 and can be electricallycoupled to a first plurality of inverters 4600 and a second plurality ofinverter 4650 respectively. When a machine associated with energymanagement system 4000 is under propulsion, first plurality of inverters4600 and second plurality of inverters 4650 can be adapted to receive DCsignals from first section of the DC bus 4400 and second section of theDC bus 4450. First plurality of inverters 4600 and second plurality ofinverters 4650 can convert DC signals to AC signals and provide ACsignals to a first traction motor 4700 and a second traction motor 4750respectively. Each of first traction motor 4700 and second tractionmotor 4750 can comprise a double stator winding adapted to receive sixphases of electric signals from first plurality of inverters 4600 andsecond plurality of inverters 4650 respectively. First plurality ofinverters 4600 and second plurality of inverters 4650 can each compriseactive IGBT components and can be PWM or SVM inverters. Because thesystem can be regenerative, four quadrant inverters can be providedamong first plurality of inverters 4600 and/or second plurality ofinverters 4650.

Traction motor 4700 and/or traction motor 4750 can be equipped withsensors adapted to provide information to a user and/or informationdevice regarding traction motor 4700 and/or traction motor 4750. Sensorscan be adapted to measure, for example, temperature, bearing vibration,motor speed, electric voltage, electric voltage phase information,electric current amps, and/or electric current phase information, etc.

Energy management system 4000 can comprise a first DC chopper circuit4500 and a second DC chopper circuit 4550. First DC chopper 4500 andsecond DC chopper 4550 can comprise one or more IGBT transistors, lowinductance bus connections, a firing circuit to turn on/off the IGBTs,current and voltage transducers and a digital control circuit. First DCchopper 4500 and second DC chopper 4550 can take a relatively constantvoltage signal from first section of DC bus 4400 and/or second sectionof DC bus 4450 as an input and use the IGBTs to switch this constantvoltage input through to the output. Using pulse width modulation theconstant input voltage can be transferred into a variable voltageoutput.

First DC chopper circuit 4500 can be electrically coupled to firstsection of the DC bus 4400. First DC chopper circuit 4500 can be adaptedto provide power to an energy dissipation device comprising a heat sinksuch as a first resister bank 4575. Second DC chopper circuit 4550 canbe electrically coupled to second section of the DC bus 4450. Second DCchopper circuit 4550 can be adapted to provide power to an energydissipation device comprising a heat sink such as a second resister bank4590.

DC choppers 4500, 4550 can generate a Pulse Wave Modulated (PWM) DCvoltage having a duty cycle (“on time”) that can be continuously variedto affect the time-averaged voltage output from DC choppers 4500, 4550to a power sink such as resistor banks 4575, 4590. Resistor banks 4575,4590 can, for example, comprise a grid resistor that can convertelectrical energy to heat. DC choppers 4500, 4550 can be used when thereis excess energy on the DC bus sections 4400, 4450 and can be adaptedtransfer excess energy into heat in resistor banks 4575, 4590.Otherwise, excessive voltages might occur on DC bus sections 4400, 4450.

If there is a need for the traction motors to retard (e.g., slow themotion of the equipment, such as when descending a grade), any AC powerthat is unneeded can be rectified and/or provided to DC bus sections4400, 4450, where the unwanted electrical energy can be provided via DCchoppers 4500, 4550 to resistor banks 4575, 4590.

Each of first DC chopper circuit 4500 and second DC chopper circuit 4550can comprise active IGBT components, which can be adapted to modulate aconstant unmodulated DC voltage and provide the modulated DC voltage toresistor bank 4575 and resistor bank 4590.

First section of the DC bus 4400 and/or second section of the DC bus4450 can be electrically coupled to an auxiliary system inverter 4800.Auxiliary system inverter 4800 can comprise IGBT components and canprovide PWM AC signals or SVM AC signals. Auxiliary system inverter 4800can be adapted to receive DC signals from first section of the DC bus4400 and/or second section of the DC bus 4450 and to provide AC signalsto an auxiliary system transformer 4850. Auxiliary transformer 4850 canreceive, for example, an AC voltage between approximately 1200 andapproximately 2000 Volts and convert the AC signals to a voltage ofapproximately 440 Volts. Transformer 4850 can be electrically coupled toa plurality of auxiliary system devices 4900 and 4950. In certainexemplary embodiments, one or more auxiliary system devices 4900 and4950 can be driven through a starter such as starter 4920.

Energy management system 4000 can be used for new machines or as aretrofit for existing machines. Certain exemplary embodiments can createthe following operational improvements: i) reduction of the HarmonicCurrent Distortion; ii) full regenerative operation; iii) high tolerancefor AC voltage fluctuations; iv) improved dynamic performance, and/or,as result, v) higher availability and productivity of machines. Thesecan be benefits of using active front ends on machines such as miningshovels and draglines.

FIG. 5 is a block diagram of a heat dissipation system 5000. Certainexemplary embodiments can comprise a water cooled system, which can beapplied to cool traction inverter systems of machines. In certainexemplary embodiments, heat dissipation system 5000 can be applied tolarge machines, such as IGBT-based AC mining trucks. In certainexemplary embodiments, heat dissipation system 5000 can be applied tomachines that utilize insulated gate bipolar transistor (IGBT) phasemodules in the drive system. Heat generators such as inverters 4600 and4650 and/or resistor bank 4575 and 4590 of FIG. 4 and/or other heatsources (such as a heat exchanger) can be comprised in a heatdissipation system 5000. Heat dissipation system 5000 can be adapted toremove energy, for example, when a machine comprising heat dissipationsystem 5000 is under retard and traction motors, such as traction motor4700 and 4750 of FIG. 4, are generating power with the machine underretard.

Heat dissipation system 5000 can comprise a fluid-to-air heat exchanger5100, which can comprise a blower 5150. Blower 5150 can improve heattransfer efficiency in fluid-to-air heat exchanger 5100 by pushing airacross the fins of fluid-to-air heat exchanger 5100, thereby removingheat therefrom. The fluid in fluid-to-air heat exchanger 5100 can bewater, glycol, and/or any other heat exchange fluid or mixture of heatexchange fluid.

Heat dissipation system 5000 can comprise a pump 5200 to circulate thefluid through a plurality of heat sources 5800 and through fluid-to-airheat exchanger 5100. Heat sources 5800 can comprise converter phasemodules, resistors, grid resistors, IGBT based rectifiers, IGBT basedinverters, and/or IGBT devices/power diodes mounted on heat sinks. Forexample, phase modules of the traction drive system can generate lossesas a result of switching under voltage high currents on and off, etc.The heat can be transferred from IGBTs to water-cooled heat sinksmounted on heat sources 5800 that can be bolted to the under-side ofIGBTs, which can be the insulated side. Once the heat is in heat sinksmounted on heat sources 5800, pump 5200 can power circulation of theheat exchange fluid through piping internal to the heat sinks mounted onheat sources 5800. The heat can be transferred in a similar way fromheat sinks mounted on heat sources 5800 to the heat exchange fluid fromIGBTs of the phase modules that are connected in parallel. Heatdissipation system 5000 can comprise a pressure sensor 5300 and/or atemperature sensor 5400. Pressure sensor 5300 and/or temperature sensor5400 can be used to analyze the performance of heat dissipation system5000.

Heat dissipation system 5000 can comprise an information device 5900,which can be communicatively coupled to pressure sensor 5300 and/ortemperature sensor 5400. When properly operating, heat dissipation 5000can prevent heat damage to electrical components such as heat sources5800. If the temperature exceeds certain thresholds then informationdevice 5900 can initiate protective measures. The signals provided toheat sources 5800 can be de-rated and/or reduced via a informationdevice 5900 responsive to the temperature exceeding a predeterminedthreshold. Responsive to the temperature exceeding the predeterminedthreshold, a flag signal can be sent to via information device 5900indicating that maintenance is required. Pressure sensor 5300 candetermine whether the pressure is in an acceptable range such as betweenapproximately 0.5 and approximately 20.99 bar and/or any value orsubrange therebetween. Heat dissipation system 5000 can comprise aninternal fluid-to-air heat exchanger 5700, which can comprise a blower5600.

Certain exemplary embodiments of heat dissipation system 5800 canoperate in an ambient air temperature of approximately −50.1° C. throughapproximately 65.5° C., and all values and/or subranges therebetween. Incertain exemplary embodiments, a reverse process can occur in parallel,which can cool internal ambient air of a sealed cabinet usingfluid-to-air heat exchanger 5700 and blower 5600 inside a tractioncabinet, as part of heat dissipation system 5000. As a result, this canaid in cooling modules within a cabinet.

In certain exemplary embodiments, machines utilizing heat dissipationsystem 5000 can operate traction converter phase modules at a higherpower rating than would otherwise be possible. As a result, in certainexemplary embodiments, fewer modules can be used for the same powerrating with fluid-cooling in contrast to conventional air-coolingsystems. Since fewer modules can be used, costs can be decreased. Afluid-cooled system can provide for more effective cooling than anair-cooled system. Improved cooling can result in higher systemreliability. Mean Time Between Failure for cooled components can bereduced since the component temperature deviations and/or swings can bereduced. in certain exemplary embodiments, fluid-cooled systems canproduce greater cooling capability in a given operating space and/orutilize a smaller enclosure than air-cooled system. Certain exemplaryembodiments can use an anti-freeze/water mix.

FIG. 9 is a block diagram of a water cooled IGBT control box 9000.

FIG. 10 is a block diagram of a water cooled IGBT control box 10000.

FIG. 11 is an illustrative diagram of a traction motor 11000.

FIG. 12 is a flow diagram of an exemplary embodiment of an energymanagement method 12000, which at activity 12100 can comprise generatingelectrical energy, such as via an alternator mechanically coupled to aninternal combustion engine. The internal combustion engine andalternator can be associated with a machine such as an off-road tractionvehicle. Mechanical energy can be transmitted from the internalcombustion engine to the alternator. The alternator can generate signalsof a voltage of approximately 120, 135.67, 159.1, 224.5, 455, 460.75,885, 930.1, 1200, 1455.45, 1687.1, 2000, 2200.32, 2300.12, 3000.6, 5500Volts and/or any other value or range of voltages therebetween. Thevoltage can be varied by changing the speed of the internal combustionengine and/or changing the excitation of the alternator. The voltagegenerated by the alternator can be of any frequency, such asapproximately 29.98 Hz, 40 Hz, 48.75 Hz, 54.2 Hz, 60 Hz, 69.2 Hz, 77.32Hz, 85.9 Hz, 99.65 Hz, 120 Hz, 144.2 Hz, 165.54 Hz, 190.3, 240 Hz and/orany value or sub-range of values therebetween.

At activity 12200, energy management method 12000 can compriserectifying and/or converting electrical energy provided to the rectifieras alternating current to a substantially unmodulated direct current.The rectifier can be an active Insulated Gate Bipolar Transistorrectifier or press pack diode rectifier comprising transistors.Additional information regarding press pack diodes can be found, forexample, in U.S. Pat. No. 6,281,569 (Sugiyama), which is incorporated byreference in its entirety. The rectifier can be electrically coupled totwo parts of a DC bus.

At activity 12300, energy management method 12000 can comprise invertingelectrical energy. Substantially unmodulated direct current from the DCbus can be inverted to an alternating current. Inverters can provideelectrical energy as an Alternating Current to auxiliary devices and/ortraction motors adapted to drive the machine. Inverters can be activeInsulated Gate Bipolar Transistor inverters.

At activity 12400, energy management method 12000 can comprisegenerating electrical energy at a traction motor. When the machine iscapable of traveling and under retard, the traction motor can act as agenerator providing signals as an Alternating Current to an inverter.Where the traction motor comprises a double stator winding, generatedsignals can be at a frequency of, for example, approximately 120 Hz. Thevoltage generated by the traction motor can be of any frequency, such as40 Hz, 48.75 Hz, 54.2 Hz, 60 Hz, 69.2 Hz, 77.32 Hz, 85.9 Hz, 99.65 Hz,120 Hz, 144.2 Hz, 165.54 Hz, 190.3, 240 Hz and/or any value or sub-rangeof values therebetween. The generated signals can be rectified, by aninverter associated with the traction motor, to a substantiallyunmodulated DC current. The substantially unmodulated DC current can beprovided to the DC bus.

At activity 12500, energy management method 12000 can comprise choppingelectrical energy at a DC chopper. The DC chopper can be an activeInsulated Gate Bipolar Transistor DC chopper. The DC chopper can beadapted to modulate the substantially unmodulated DC current. Modulatingthe substantially unmodulated DC current can allow surplus electricalenergy to be dissipated via a device utilizing the Hall effect.

At activity 12600, energy management method 12000 can compriseconverting electrical energy to heat energy at a heat sink. In certainexemplary embodiments, the heat sink can be mechanically fastened to aheat generating electrical device, such as a resistor and/or aninverter. In certain exemplary embodiments, the electrical energy can beconverted to heat energy utilizing resistors such as a resistor grid. Incertain exemplary embodiments, the electrical energy can be converted toheat energy utilizing a coil to transfer the electrical energy to a massassociated with the machine adapted to dissipate the heat. The resistorand/or mass can dissipate the heat energy to a surrounding environmentvia, for example, convective heat transfer to air surrounding thevehicle and/or conductive heat transfer to substances in contact withthe mass. Convective heat transfer can be improved by utilizing a blowerto move air around heated resistors and/or masses.

FIG. 13 is a block diagram of an exemplary embodiment of an informationdevice 13000, which in certain operative embodiments can comprise, forexample, information device 1200 of FIG. 1. Information device 15000 cancomprise any of numerous well-known components, such as for example, oneor more network interfaces 13100, one or more processors 13200, one ormore memories 13300 containing instructions 13400, one or moreinput/output (I/O) devices 13500, and/or one or more user interfaces13600 coupled to I/O device 13500, etc.

In certain exemplary embodiments, via one or more user interfaces 13600,such as a graphical user interface, a user can view a rendering ofinformation related to a machine.

Still other embodiments will become readily apparent to those skilled inthis art from reading the above-recited detailed description anddrawings of certain exemplary embodiments. It should be understood thatnumerous variations, modifications, and additional embodiments arepossible, and accordingly, all such variations, modifications, andembodiments are to be regarded as being within the spirit and scope ofthis application. For example, regardless of the content of any portion(e.g., title, field, background, summary, abstract, drawing figure,etc.) of this application, unless clearly specified to the contrary,such as via an explicit definition, there is no requirement for theinclusion in any claim herein (or of any claim of any applicationclaiming priority hereto) of any particular described or illustratedcharacteristic, function, activity, or element, any particular sequenceof activities, or any particular interrelationship of elements.Moreover, any activity can be repeated, any activity can be performed bymultiple entities, and/or any element can be duplicated. Further, anyactivity or element can be excluded, the sequence of activities canvary, and/or the interrelationship of elements can vary. Accordingly,the descriptions and drawings are to be regarded as illustrative innature, and not as restrictive. Moreover, when any number or range isdescribed herein, unless clearly stated otherwise, that number or rangeis approximate. When any range is described herein, unless clearlystated otherwise, that range includes all values therein and allsubranges therein. Any information in any material (e.g., a UnitedStates patent, United States patent application, book, article, etc.)that has been incorporated by reference herein, is only incorporated byreference to the extent that no conflict exists between such informationand the other statements and drawings set forth herein. In the event ofsuch conflict, including a conflict that would render invalid any claimherein or seeking priority hereto, then any such conflicting informationin such incorporated by reference material is specifically notincorporated by reference herein.

1. A method comprising a plurality of activities, said activitiescomprising: for an off-road traction vehicle: from an alternator,receiving a first AC signal at an active Insulated Gate BipolarTransistor rectifier, the active Insulated Gate Bipolar Transistorrectifier electrically coupled to a DC bus; and via an inverterelectrically coupled to the DC bus, providing a second AC signal to atraction motor comprising a double stator winding.
 2. The method ofclaim 1, further comprising: via the active Insulated Gate BipolarTransistor rectifier, converting the first AC signal received from thealternator to a DC signal.
 3. The method of claim 1, further comprising:from the active Insulated Gate Bipolar Transistor rectifier, providing aDC signal to the DC bus.
 4. The method of claim 1, further comprising:at an active Insulated Gate Bipolar Transistor DC chopper, receiving anunmodulated DC signal from the DC bus.
 5. The method of claim 1, furthercomprising: at an active Insulated Gate Bipolar Transistor DC chopper,receiving an unmodulated DC signal from the DC bus; and via the activeInsulated Gate Bipolar Transistor DC chopper, providing a modulated DCsignal to a heat sink.
 6. The method of claim 1, further comprising: viaan internal combustion engine mechanically coupled to the alternator,transmitting mechanical energy to the alternator.
 7. The method of claim1, further comprising: varying a voltage on the DC bus responsive to achanged speed of an internal combustion engine mechanically coupled tosaid alternator.
 8. The method of claim 1, further comprising: varying avoltage on the DC bus is responsive to a changed alternator excitation.9. The method of claim 1, further comprising: via the active InsulatedGate Bipolar Transistor rectifier, limiting harmonic current distortionto approximately 5 percent.
 10. The method of claim 1, furthercomprising: via the active Insulated Gate Bipolar Transistor rectifier,limiting harmonic current distortion to approximately 3 percent.
 11. Themethod of claim 1, further comprising: via the active Insulated GateBipolar Transistor rectifier, limiting harmonic current distortion toapproximately 2 percent.
 12. The method of claim 1, further comprising:via the active Insulated Gate Bipolar Transistor rectifier, providing anactive input power factor correction to approximately 0.98.
 13. Themethod of claim 1, further comprising: via the active Insulated GateBipolar Transistor rectifier, providing an active input power factorcorrection to approximately 0.99.
 14. The method of claim 1, furthercomprising: via the active Insulated Gate Bipolar Transistor rectifier,providing an active input power factor correction to approximately 1.0.15. The method of claim 1, further comprising: via the active InsulatedGate Bipolar Transistor inverter generating a space vector modulated ACvoltage.
 16. The method of claim 1, further comprising: via the activeInsulated Gate Bipolar Transistor inverter, providing a sinusoidaloutput current with less than approximately 5 percent total harmonicdistortion to the traction motor.
 17. A method comprising: an electricdrive system for a mining haul truck, comprising: at an active InsulatedGate Bipolar Transistor inverter, converting a first AC signal receivedfrom a traction motor to an unmodulated DC signal, the unmodulated DCsignal adapted to be provided to a DC bus, the active Insulated GateBipolar Transistor rectifier electrically coupled to the DC bus; at anactive Insulated Gate Bipolar Transistor DC chopper, converting theunmodulated DC signal from the DC bus to a modulated DC signal; andproviding the modulated DC signal to a heat sink.
 18. A methodcomprising: for an electric drive system for a mining machine,comprising: at an active Insulated Gate Bipolar Transistor rectifier,converting a first AC signal from an alternator to a DC signal, theactive Insulated Gate Bipolar Transistor rectifier electrically coupledto a DC bus; and via an active Insulated Gate Bipolar Transistorinverter electrically coupled to the DC bus, generating a space vectormodulated AC signal.
 19. The method of claim 18, further comprising: atan active Insulated Gate Bipolar Transistor DC chopper, receiving anunmodulated DC signal from the DC bus.
 20. The method of claim 18,further comprising: at an active Insulated Gate Bipolar Transistor DCchopper, converting an unmodulated DC signal received from the DC bus toa modulated DC signal; and providing the modulated DC signal to a heatsink.